Lens driving device, camera module, and camera-mounted device

ABSTRACT

Provided are a lens driving device, a camera module, and a camera-mounted device for which the miniaturization and weight reduction can be achieved and the reliability can also be improved. The lens driving device includes AF and shake-correcting driving parts utilizing a voice coil motor. An AF fixing part includes an AF control part controlling the energization current through an AF coil part. The AF driving part includes upper and lower elastic supporting parts, auto-focusing power-source lines connected to power-supplying suspension wires functioning as a shake-correcting supporting part, signal lines connected to signal suspension wires functioning as a shake-correcting supporting part, and coil power-supply lines electrically connecting the AF control part to the AF coil part. The upper elastic supporting part functions at least as the AF power-supply lines or the signal lines, and the lower elastic supporting part functions as the coil power-supply lines.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is entitled to and claims the benefit of JapanesePatent Application No. 2017-119945, filed on Jun. 19, 2017, thedisclosure of which including the specification, drawings and abstractis incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a lens driving device for auto-focusingand shake-correcting, a camera module, and a camera-mounted device.

BACKGROUND ART

In general, a small-sized camera module is mounted in mobile terminals,such as smartphones. A lens driving device having an autofocus functionof automatically performing focusing during capturing of a subject(hereinafter referred to as “AF (Auto Focus) function”) and ashake-correcting function (hereinafter referred to as “OIS (OpticalImage Stabilization) function”) for reducing irregularities of an imageby correcting shake (vibration) caused during capturing of an image isapplied in such a camera module (see e.g. Patent Literatures(hereinafter referred to as “PTLs”) 1 and 2).

The lens driving device including the autofocus and shake-correctingfunctions is provided with an auto-focusing driving part for moving alens part in the optical-axis direction (hereinafter, the auto-focusingdriving part is referred to as “AF driving part”) and a shake-correctingdriving part for swaying the lens part in a plane orthogonal to theoptical-axis direction (hereinafter, the shake-correcting driving partis referred to as “OIS driving part”). In PTLs 1 and 2, a voice coilmotor (VCM) is employed in the AF driving part and the OIS driving part.

The AF driving part of a VCM-driven system includes, for example, anauto-focusing coil part (hereinafter referred to as “AF coil part”)disposed at the periphery of the lens part, and an auto-focusing magnetpart (hereinafter referred to as “AF magnet part”) disposed to beradially spaced apart from the AF coil part. An autofocus movable part(hereinafter referred to as “AF movable part”) including the lens partand the AF coil part is supported by an auto-focusing supporting part(hereinafter referred to as “AF supporting part” (e.g. plate spring))such that the AF movable part is radially spaced apart from an autofocusfixing part (hereinafter referred to as “AF fixing part”) including theAF magnet part. Focusing is automatically carried out by moving the AFmovable part in the optical-axis direction by utilizing a driving forceof the voice coil motor composed of the AF coil part and the AF magnetpart.

The OIS driving part of the VCM-driven system includes, for example, ashake-correcting magnet part (hereinafter referred to as “OIS magnetpart”) disposed in the AF driving part and a shake-correcting coil part(hereinafter referred to as “OIS coil part”) disposed to be spaced apartfrom the OIS magnet part in the optical-axis direction. Ashake-correcting movable part (hereinafter referred to as “OIS movablepart”) including the AF driving part and the OIS magnet part issupported by shake-correcting supporting parts (hereinafter referred toas “OIS supporting parts” (e.g. suspension wires)) such that theshake-correcting movable part is spaced apart in the optical-axisdirection from a shake-correcting fixing part (hereinafter referred toas “OIS fixing part”) including the OIS coil part. Shake correction isperformed by swaying the OIS movable part with respect to the OIS fixingpart in the plane orthogonal to the optical-axis direction by utilizingthe driving force of the voice coil motor composed of the OIS magnetpart and the OIS coil part.

CITATION LIST Patent Literature PTL 1: Japanese Patent ApplicationLaid-Open No. 2013-210550 PTL 2: Japanese Patent Application Laid-OpenNo. 2012-177753 SUMMARY OF INVENTION Technical Problem

In recent years, there has been a demand for further miniaturization andfurther weight reduction of lens driving devices in order to achieve theminiaturization (thickness reduction) and/or weight reduction ofcamera-mounted devices, such as smartphones and the like.

An object of the present invention is to provide a lens driving device,a camera module, and a lens driving device for which the miniaturizationand weight reduction can be achieved and the reliability can also beimproved.

Solution to Problem

A lens driving device according to the present invention includes anauto-focusing driving part including: an auto-focusing coil part to bedisposed at a periphery of a lens part; an auto-focusing magnet part tobe disposed to be radially spaced apart from the auto-focusing coilpart; and an auto-focusing supporting part configured to support anautofocus movable part to be movable in an optical-axis direction withrespect to an autofocus fixing part, the autofocus movable partincluding the auto-focusing coil part, the autofocus fixing partincluding the auto-focusing magnet part, the auto-focusing driving partbeing configured to perform automatic focusing by utilizing a drivingforce of a voice coil motor composed of the auto-focusing coil part andthe auto-focusing magnet part, and the lens driving device also includesa shake-correcting driving part including: a shake-correcting magnetpart to be disposed in the auto-focusing driving part; ashake-correcting coil part to be disposed to be spaced apart from theshake-correcting magnet part in the optical-axis direction; and ashake-correcting supporting part configured to support ashake-correcting movable part to be able to sway in anoptical-axis-orthogonal plane with respect to a shake-correcting fixingpart, the shake-correcting movable part including the shake-correctingmagnet part, the shake-correcting fixing part including theshake-correcting coil part, the shake-correcting driving part beingconfigured to perform shake correction by utilizing a driving force ofan another voice coil motor composed of the shake-correcting coil partand the shake-correcting magnet part. The auto-focusing supporting partincludes an upper elastic supporting part configured to couple theautofocus movable part and the autofocus fixing part together at a lightreception side in the optical-axis direction, and a lower elasticsupporting part configured to couple the autofocus movable part and theautofocus fixing part together at an image formation side in theoptical-axis direction. The shake-correcting supporting part includes apair of power-supplying suspension wires each of which includes one endto be connected to the autofocus fixing part and the other end to beconnected to the shake-correcting fixing part, and a pair of signalsuspension wires each of which includes one end to be connected to theautofocus fixing part and the other end to be connected to theshake-correcting fixing part. The autofocus movable part includes a lensholder including a cylindrical lens housing configured to hold the lenspart and a coil winding portion on which the auto-focusing coil part iswound, and a position-detecting magnet to be disposed to the lensholder. The autofocus fixing part includes an auto-focusing control partto be electrically connected to the pair of power-supplying suspensionwires and the pair of signal suspension wires, the auto-focusing controlpart being configured to control an energization current through theauto-focusing coil part. The auto-focusing driving part includes a pairof auto-focusing power-supply lines to be connected to the pair ofpower-supplying suspension wires, a pair of signal lines to be connectedto the pair of signal suspension wires, and a coil power-supply lineconfigured to electrically connect the auto-focusing control part to theauto-focusing coil part. The auto-focusing control part includes acontrol IC including a built-in Hall element and a built-in coil controlpart, the built-in coil control part being configured to control theenergization current through the auto-focusing coil part based on acontrol signal to be provided via the pair of signal suspension wiresand based on a detection result of the built-in Hall element, and anauto-focusing printed wiring board on which the control IC is mounted.The upper elastic supporting part functions at least as the pair ofauto-focusing power-supply lines or the pair of signal lines, and thelower elastic supporting part functions as the coil power-supply line.

A camera module according to the present invention includes: theaforementioned lens driving device; a lens part to be mounted on theautofocus movable part; and an image capturing part configured tocapture a subject image imaged by the lens part.

A camera-mounted device according to the present invention is acamera-mounted device that is an information device or a transportingdevice, and includes: the aforementioned camera module; and a controlpart configured to process image information obtained by the cameramodule.

Advantageous Effects of Invention

According to the present invention, it is possible to achieve theminiaturization and weight reduction of a lens driving device, a cameramodule, and a camera-mounted device and to improve the reliability ofthe lens driving device, camera module, and camera-mounted device.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B illustrate a smartphone in which a camera moduleaccording to an embodiment of the present invention is mounted;

FIG. 2 is a perspective view of an external appearance of the cameramodule.

FIG. 3 is an exploded perspective view of the camera module.

FIG. 4 is an exploded perspective view of the camera module.

FIG. 5 is an exploded perspective view of a lens driving device.

FIG. 6 is an exploded perspective view of the lens driving device.

FIG. 7 is an exploded perspective view of an OIS movable part.

FIG. 8 is an exploded perspective view of the OIS movable part.

FIG. 9 is a perspective view illustrating arrangement ofposition-detecting magnets and an AF printed wiring board;

FIG. 10 is a plan view illustrating the directions of the magneticfields at an AF movable part;

FIGS. 11A and 11B are sectional views of the YZ plane through a firstposition-detecting magnet;

FIGS. 12A and 12B illustrate a configuration of an AF control part;

FIG. 13 is a plan view illustrating a configuration of an upper elasticsupporting part and AF power-supply lines;

FIG. 14 illustrates a configuration of a lower elastic supporting part;

FIG. 15 is an exploded perspective view of an OIS fixing part;

FIG. 16 is an exploded perspective view of the OIS fixing part;

FIGS. 17A and 17B illustrate a configuration of a base;

FIG. 18 illustrates a stack structure of a coil board;

FIGS. 19A and 19B are bottom views illustrating a structure of the coilboard;

FIG. 20 illustrates a supporting structure of the OIS fixing part andthe OIS movable part; and

FIGS. 21A and 21B illustrate an automobile as a camera-mounted device inwhich an in-vehicle camera module is mounted.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the invention will be described in detailwith reference to the accompanying drawings.

FIGS. 1A and 1B illustrate smartphone M (camera-mounted device) in whichcamera module A according to embodiments of the present invention ismounted. FIG. 1A is a front view of smartphone M and FIG. 1B is a rearview of smartphone M.

Smartphone M is provided with camera module A, for example, as back sidecamera OC. Camera module A has an AF function and an OIS function, andcan capture an image without image blurring by automatically performingfocusing at the time of capturing a subject and by optically correctingshake (vibration) caused at the time of capturing the image.Additionally, smartphone M includes a control part (not illustrated)configured to process image information obtained by camera module A.

FIG. 2 is a perspective view of an external appearance of camera moduleA. FIGS. 3 and 4 are exploded perspective views of camera module A. FIG.3 is an upper perspective view and FIG. 4 is a lower perspective view.The embodiments will be described using an orthogonal coordinate system(X, Y, Z) as illustrated in FIGS. 2 to 4. The same orthogonal coordinatesystem (X, Y, Z) is also used for illustration of below-mentionedfigures. Moreover, in the descriptions, the intermediate directions ofthe X and Y directions, that is, the diagonal directions in theplan-view shape of camera module A as seen in the Z direction arereferred to as the U direction and V direction (see FIG. 10).

Camera module A is mounted such that the vertical direction (orhorizontal direction) is the X direction, the horizontal direction (orvertical direction) is the Y direction, and the front-rear direction isthe Z direction during actually capturing an image with smartphone M.That is, the Z direction is the optical-axis direction, the upper sidein the figures is the light reception side in the optical-axisdirection, and the lower side is the image formation side in theoptical-axis direction. In addition, the X and Y directions orthogonalto the Z axis are referred to as “optical-axis-orthogonal directions”and the XY plane is referred to as “optical-axis-orthogonal plane.”

Camera module A includes lens driving device 1 that achieves the AFfunction and the OIS function, a lens part (not illustrated) composed ofa cylindrical lens barrel and a lens housed therein, an image capturingpart (not illustrated) configured to capture a subject image imaged bythe lens part, cover 2 entirely covering camera module A, and the like.

Cover 2 is a capped rectangular cylindrical member having a square shapein plan view as seen in the optical-axis direction. Cover 2 includes, inits upper surface, substantially circular opening 2 a. The lens part(not illustrated) faces outside from this opening 2 a. Cover 2 is fixedto base 21 (see FIGS. 15 and 16) of OIS fixing part 20 of lens drivingdevice 1.

At the upper surface of cover 2, distance Lx between second cover edge 2c extending along the Y axis and opening 2 a is shorter than distance Lybetween first cover edge 2 b extending along the X axis and opening 2 a.That is, first cover edge 2 b is shorter than second cover edge 2 c. Inthis way, camera module A has an external shape in plan view that issmaller than a square with a side length the same as second cover edge 2c; that is, the miniaturization is achieved (slim border design isachieved).

The image capturing part (not illustrated) is disposed on the imageformation side of lens driving device 1 in the optical-axis direction.The image capturing part includes, for example, an imaging device (notillustrated) such as a charge-coupled device (CCD) image sensor, acomplementary metal oxide semiconductor (CMOS) image sensor, or the likeand a sensor board on which the imaging device is mounted. The imagingdevice captures a subject image imaged by the lens part (notillustrated). Lens driving device 1 is mounted on the sensor board (notillustrated) and electrically connected to the sensor board.

FIGS. 5 and 6 are exploded perspective views of lens driving device 1.FIG. 5 is an upper perspective view and FIG. 6 is a lower perspectiveview.

As illustrated in FIGS. 5 and 6, lens driving device 1 includes OISmovable part 10, OIS fixing part 20, OIS supporting part 30, and thelike.

OIS movable part 10 includes an OIS magnet part being a component of anOIS voice coil motor, and sways in the optical-axis-orthogonal planeduring shake correction. OIS fixing part 20 includes an OIS coil partbeing a component of the OIS voice coil motor, and supports OIS movablepart 10 via OIS supporting part 30. That is, the moving-magnet system isemployed in the OIS driving part of lens driving device 1. OIS movablepart 10 includes an AF driving part (AF movable part 11 and AF fixingpart 12 (see FIGS. 7 and 8)).

OIS movable part 10 is disposed to be spaced apart from OIS fixing part20 on the light reception side in the optical-axis direction, and iscoupled to OIS fixing part 20 by OIS supporting part 30. Specifically,OIS supporting part 30 is composed of four suspension wires extending inthe optical-axis direction (hereinafter referred to as “suspension wires30”). One ends (upper ends) of suspension wires 30 are fixed to OISmovable part 10 (to AF supporting part 13, AF power-supply lines 171 and172 (see FIGS. 7 and 8)), and the other ends (lower ends) are fixed toOIS fixing part 20 (to base 21, (see FIGS. 15 and 16)). OIS movable part10 is supported by suspension wires 30 in such a manner as to be able tosway in the optical-axis-orthogonal plane.

In the embodiments of the present invention, suspension wires 31A and31B of four suspension wires 30 are used as signal paths for conveyingcontrol signals to AF control part 16 (control IC 161 (see FIG. 12A))(these suspension wires 31A and 31B may also hereinafter be referred toas “signal suspension wires 31A and 31B”). Suspension wires 32A and 32Bare used as power-supplying paths to AF control part 16 (control IC 161)(these suspension wires 32A and 32B may also hereinafter be referred toas “power-supplying suspension wires 32A and 32B”).

FIGS. 7 and 8 are exploded perspective views of OIS movable part 10.FIG. 7 is an upper perspective view and FIG. 8 is a lower perspectiveview.

As illustrated in FIGS. 7 and 8, OIS movable part 10 includes AF movablepart 11, AF fixing part 12, AF supporting parts 13 and 14, AFpower-supply lines 171 and 172, and the like. AF movable part 11 isdisposed to be radially inwardly spaced apart from AF fixing part 12,and is coupled to AF fixing part 12 by AF supporting parts 13 and 14.

AF movable part 11 includes AF coil part 112 being a component of the AFvoice coil motor, and moves in the optical-axis direction duringfocusing. AF fixing part 12 includes magnet part 122 (AF magnet part)being a component of the AF voice coil motor, and supports AF movablepart 11 via AF supporting parts 13 and 14. That is, the moving-coilsystem is employed in the AF driving part of lens driving device 1.

AF movable part 11 includes lens holder 111, AF coil part 112, andposition-detecting magnet 15 (see FIG. 7).

Lens holder 111 includes cylindrical lens housing 111 a and upper flange111 b and lower flange 111 c each protruding radially outward from lenshousing 111 a. That is, lens holder 111 includes a bobbin structure.Upper and lower flanges 111 b and 111 c have a substantially octagonalshape in plan view. The upper surface of upper flange 111 b serves as alocking portion for restricting the movement of AF movable part 11toward the light reception side in the optical-axis direction.

AF coil part 112 is wound on a portion sandwiched between upper andlower flanges 111 b and 111 c (this portion may also hereinafter bereferred to as “coil winding portion”). The coil winding portion (whosereference numeral is omitted) has a substantially regular octagonalshape in plan view. With this configuration, a load to be applied to thecoil winding portion when AF coil part 112 is wound directly on the coilwinding portion is made uniform, and the strength of the coil windingportion is also made substantially uniform relative to the center, sothat deformation of the opening of lens housing 111 a can be preventedand the roundness can be maintained.

It is preferable that the inner peripheral surface of lens housing 111 ainclude a groove (not illustrated) to which an adhesive is applied. In acase of the method for mounting the lens part (not illustrated) to lenshousing 111 a by screwing, there is a risk that suspension wires 30supporting OIS movable part 10 may be damaged. In contrast, in theembodiments of the present invention, the lens part (not illustrated) isadhesively fixed to the inner peripheral surface of lens housing 111 a,so that suspension wires 30 can be prevented from being damaged duringattachment of the lens part. Additionally, the groove in the innerperipheral surface of lens housing 111 a holds therein a proper amountof adhesive, so that the adhesive strength between lens holder 111 andthe lens part is enhanced.

Lens holder 111 includes four upper-spring fixing portions 111 d usedfor fixing AF supporting part 13 at the upper outer periphery of lenshousing 111 a. Lens holder 111 includes four lower-spring fixingportions 111 g used for fixing AF supporting part 14 at the undersurfaceof lower flange 111 c.

Lens holder 111 also includes magnet housings 111 f that houseposition-detecting magnets 15 (15A, 15B) at the upper outer periphery oflens housing 111 a, particularly, at portions of upper flange 111 b. Inthe embodiments of the present invention, two magnet housings 111 f aredisposed opposite each other in the Y direction that is the longitudinaldirection. Specifically speaking, magnet housings 111 f are providedrespectively at positions corresponding to the middles betweenspaced-apart permanent magnets 122A and 122B and between spaced-apartpermanent magnets 122C and 122D adjacent to each other in the Xdirection that is the transverse direction. Note that, magnet housings111 f may also be provided at portions of lower flange 111 c.

Lens holder 111 includes tying parts 111 e protruding radially outwardfrom two of four lower-spring fixing portions 111 g. Ends of AF coilpart 112 are tied to tying parts 111 e, respectively. Lens holder 111also includes protruding portions 111 h radially protruding to isolateeach of tying parts 111 e. One of protruding portions 111 h is disposedbetween tying parts 111 e. Protruding portions 111 h spatially separatefrom each other the both ends of AF coil part 112 tied to tying parts111 e, to secure the insulation property, so as to improve the safetyand reliability.

Lens holder 111 also includes holder-side contact portions 111 i atportions of lower flange 111 c. Holder-side contact portions 111 iprotrude beyond their respective surrounding regions on the imageformation side in the optical-axis direction. The undersurfaces ofholder-side contact portions 111 i serve as locking portions forrestricting the movement of AF movable part 11 toward the imageformation side in the optical-axis direction. In the embodiments of thepresent invention, two holder-side contact portions 111 i are providedopposite each other in the X direction. Holder-side contact portions 111i come into contact with the upper surface of coil board 22 (see FIGS.15 and 16) of OIS fixing part 20.

In the embodiments of the present invention, lens holder 111 is formedfrom a molding material consisting of polyarylate (PAR) or a PAR alloywhich is a mixture of multiple resin materials including PAR. Inparticular, it is preferable that the PAR alloy be a polymer alloy(PAR/PC) consisting of PAR and polycarbonate (PC). With this moldingmaterial, the weld strength is increased as compared with conventionalmolding materials (e.g. liquid crystal polymer (LCP)) and, thus, thetoughness and impact resistance can be secured even when lens holder 111is thin-walled. It is thus possible to make the external size of lensdriving device 1 smaller and to achieve the miniaturization and weightreduction.

Additionally, lens holder 111 is preferably formed by injection moldingusing multiple gates. In this case, the gate diameter is preferably 0.3mm or greater. Such injection molding brings about a better fluidityduring molding, so as to allow thin-wall molding and besides, to make itpossible to prevent occurrence of sink marks even when the PAR or PARalloy is used as molding material.

It is preferable that the molding material consisting of the PAR or PARalloy be conductive and, in particular, have a volume resistivity offrom 10⁹ Ω·cm to 10¹¹ Ω·cm. For example, it is possible to easily impartconductivity to an existing PAR or PAR alloy by mixing carbon nanotubesinto such an existing PAR or PAR alloy. At this time, suitableconductivity can be imparted by adjusting the content of carbonnanotubes. Such adjustment makes it possible to reduce electrificationof lens holder 111 and thus to prevent occurrence of static electricity.

It is also preferable that the molding material consisting of the PAR orPAR alloy contain fluoride. By the contained fluoride, theintermolecular forces become weaker, so that the adsorptive power ofportions of lens holder 111 (holder-side contact portions 111 i) cominginto contact with coil board 22 decreases and the slidability improves.Accordingly, it is possible to prevent dust generation due to frictionduring contact between lens holder 111 and coil board 22.

Thus, with the above-described configuration of lens holder 111, it ismade possible to achieve the miniaturization and weight reduction oflens driving device 1 and to improve the reliability.

AF coil part 112 is an air core coil to be energized at the time offocusing, and is wound on the outer peripheral surface of coil windingportion of lens holder 111. The both ends of AF coil part 112 are tiedto tying parts 111 e of lens holder 111, respectively. AF coil part 112is energized via AF supporting part 14 (lower plate springs 141 and142). The energization current through AF coil part 112 is controlled byAF control part 16 (control IC 161 (see FIG. 12A)).

Position-detecting magnets 15 are disposed in magnet housings 111 f oflens holder 111. That is, position-detecting magnets 15 are disposedrespectively at the positions corresponding to the middles betweenspaced-apart permanent magnets 122A and 122B and between spaced-apartpermanent magnets 122C and 122D. Position-detecting magnets 15 includefirst position-detecting magnet 15A disposed in magnet housing 111 f onthe side corresponding to AF control part 16 and secondposition-detecting magnet 15B disposed in magnet housing 111 f on theopposite side (see FIGS. 9 and 10). First position-detecting magnet 15Ais used for position detection of AF movable part 11 in the optical-axisdirection. Second position-detecting magnet 15B is a dummy magnet whichis not used for position detection of AF movable part 11.

Second position-detecting magnet 15B is disposed in order to balance themagnetic forces which act on AF movable part 11 to stabilize theattitude of AF movable part 11. That is, since, when secondposition-detecting magnet 15B is not disposed, an unbalanced magneticforce caused by the magnetic field generated by magnet part 122 acts onAF movable part 11, so as to make the attitude of AF movable part 11unstable. In order to prevent this, second position-detecting magnet 15Bis disposed.

In the embodiments of the present invention, first and secondposition-detecting magnets 15A and 15B are, like permanent magnets 122Ato 122D, radially magnetized and the magnetization directions are alsothe same as those of permanent magnets 122A to 122D (see FIGS. 9 and10). Specifically, first and second position-detecting magnets 15A and15B are magnetized such that the inner periphery side and the outerperiphery side of position-detection magnets 15A and 15B are set to Npole and S pole, respectively.

It is preferable that the width of each of first and secondposition-detecting magnets 15A and 15B in the optical-axis-orthogonaldirection (the width in the Y direction in this case) be smaller thanthe height of each of first and second position-detecting magnets 15Aand 15B in the optical-axis direction. This makes it possible to achievethin-walled lens holder 111 while securing the magnetic flux densitiesof magnetic fluxes emitted by first and second position-detectingmagnets 15A and 15B. The detailed arrangement of first and secondposition-detecting magnets 15A and 15B (positional relationship with AFcontrol part 16) will be described below.

AF fixing part 12 includes magnet holder 121, magnet part 122, yoke 123and AF control part 16.

Magnet holder 121 is a substantially rectangular cylindrical holdingmember including four side walls 121 b coupled to one another. Thelengths of those of side walls 121 b extending along the X direction areshorter than the lengths of those of side walls 121 b extending alongthe Y direction. Magnet holder 121 includes opening 121 a formed bycutting out portions corresponding to lens housing 111 a, upper-springfixing portions 111 d, and magnet housings 111 f of lens holder 111.

Magnet holder 121 includes magnet holding portions 121 c adapted to holdmagnet part 122 at the insides of coupled portions of four side walls121 b (four corners of magnet holder 121). Magnet holder 121 includeswire insertion portions 121 d depressed radially inward into the shapeof a circular arc at the outsides of the coupled portions of side walls121 b. Suspension wires 30 are disposed in wire insertion portions 121 d(see FIGS. 3 and 4). Interference between suspension wires 30 and magnetholder 121 during sway of OIS movable part 10 can be avoided byproviding wire insertion portions 121 d.

Magnet holder 121 includes stopper portions 121 e projecting radiallyinward at upper portions of side walls 121 b. When AF movable part 11moves toward the light reception side in the optical-axis direction,stopper portions 121 e come into contact with upper flange 111 b of lensholder 111, so as to restrict the movement of AF movable part 11 towardthe light reception side in the optical-axis direction. In theembodiments of the present invention, stopper portions 121 e areprovided at four places, where two of stopper portions 121 e areopposite to each other in the X direction and the other two in the Ydirection.

Magnet holder 121 includes upper-spring fixing portions 121 f for fixingAF supporting part 13 and AF power-supply lines 171 and 172 at the fourcorners of the upper surfaces of side walls 121 b. Magnet holder 121also includes lower-spring fixing portions 121 g for fixing AFsupporting part 14 on the undersurfaces of side walls 121 b extendingalong the X-axis. Magnet holder 121 also includes protruding portion 121i protruding in the optical-axis direction in such a manner as toisolate each of two of lower-spring fixing portions 121 g. Protrudingportion 121 i is disposed between adjacent lower-spring fixing portions121 g. That is, protruding portion 121 i is arranged betweenpower-supply output terminals 162 a and 162 b in the state where AFcontrol part 16 is attached (see FIG. 12). Protruding portion 121 ispatially separates power-supply output terminals 162 a and 162 b fromeach other to secure the insulation property, so as to improve thesafety and reliability.

Upper-spring fixing portions 121 f include corner portions which areeach formed with a downward depression lower than the upper surface ofmagnet holder 121 (the surface to which AF supporting part 13 or AFpower-supply lines 171 and 172 are attached), and are each formed suchthat a gap is formed between the corner portion and AF supporting part13 or AF power-supply lines 171 and 172 after attachment of AFsupporting part 13 or AF power-supply lines 171 and 172. Magnet holder121 also includes IC housing 121 h for housing AF control part 16 in oneof side walls 121 b extending along the X direction.

In the embodiments of the present invention, like lens holder 111,magnet holder 111 is formed from a molding material consisting ofpolyarylate (PAR) or a PAR alloy (e.g. PAR/PC) which is a mixture ofmultiple resin materials including PAR. With this molding material, theweld strength is increased and, thus, the toughness and impactresistance can be secured even when magnet holder 121 is thin-walled. Itis thus possible to make the external size of lens driving device 1smaller and to achieve the miniaturization and height reduction.

Additionally, magnet holder 121 is preferably formed by injectionmolding using multiple gates. In this case, the gate diameter ispreferably 0.3 mm or greater. Such injection molding brings about abetter fluidity during molding, so as to allow thin-wall molding andbesides, to make it possible to prevent occurrence of sink marks evenwhen the PAR or PAR alloy is used as molding material.

It is preferable that the molding material consisting of the PAR or PARalloy be conductive and, in particular, have a volume resistivity offrom 10⁹ Ω·cm to 10¹¹ Ω·cm. For example, it is possible to easily impartconductivity to an existing PAR or PAR alloy by mixing carbon nanotubesinto such an existing PAR or PAR alloy. At this time, suitableconductivity can be imparted by adjusting the content of carbonnanotubes. Such adjustment makes it possible to reduce electrificationof magnet holder 121 and thus to prevent occurrence of staticelectricity.

It is also preferable that the PAR or PAR alloy contain fluoride. By thecontained fluoride, the intermolecular forces become weaker, so that theadsorptive power of portions of magnet holder 121 coming into contactwith lens holder 111 decreases and the slidability improves.Accordingly, it is possible to prevent dust generation due to frictionduring contact between lens holder 111 and magnet holder 121.

Magnet part 122 includes four rectangular columnar permanent magnets122A to 122D. Permanent magnets 122A to 122D are fixed, for exampleadhesively, to magnet holding portions 121 c, respectively. In theembodiments of the present invention, permanent magnets 122A to 122Deach have the shape of a substantially isosceles trapezoid in plan view.Such a shape makes it possible to effectively utilize the spaces at thecorners of magnet holder 121 (magnet holding portions 121 c). Permanentmagnets 122A to 122D are each magnetized such that a magnetic fieldradially traversing AF coil part 112 is formed at AF coil part 112. Inthe embodiments of the present invention, permanent magnets 122A to 122Dare magnetized such that the inner periphery sides and the outerperiphery sides of permanent magnets 122A to 122D are set to N pole andS pole, respectively.

The undersurfaces of permanent magnets 122A to 122D protrude from magnetholder 122 toward the image formation side in the optical-axis direction(see FIG. 6). That is, the height of OIS movable part 10 is determinedby permanent magnets 122A to 122D. Thus, the height of OIS movable part10 can be minimized according to the sizes of permanent magnets 122A to122D enough to secure the magnetic forces, so that height reduction oflens driving device 1 can be achieved.

Permanent magnets 122A to 122D include yokes 123A to 123D disposed onthe back surfaces (surfaces on the outer periphery side) of permanentmagnets 122A to 122D. For example, yokes 123A to 123D are adhered tomagnet holding portions 121 c of magnet holder 121, and thereafter,permanent magnets 122A to 122D are adhered. The magnetic fluxes whichcross OIS coils 221A to 221D (see FIG. 15) are increased by disposingyokes 123A to 123D, so that it is possible to increase the thrust forshake-correcting operation.

Magnet part 122 and coil part 112 constitute the AF voice coil motor. Inthe embodiments of the present invention, magnet part 122 serves as bothof the AF magnet part and the OIS magnet part.

AF control part 16 includes control IC 161, bypass capacitor 163, and AFprinted wiring board 166 on which control IC 161 and bypass capacitor163 are mounted (see FIGS. 12A and 12B). AF control part 16 is fixed,for example adhesively, to IC housing 121 h of magnet holder 121. Atthis time, control IC 161 and bypass capacitor 163 are fit in theopening (whose reference numeral is omitted) of IC housing 121 h.

Control IC 161 includes built-in Hall element 165 that utilizes the Halleffect to detect the change of the magnetic field, and functions as a Zposition detector. When AF movable part 11 moves in the optical-axisdirection, the magnetic field by first position-detecting magnet 15Achanges. Hall element 165 detects this change in magnetic field, andaccordingly, the position of AF movable part 11 in the optical-axisdirection is detected. The layouts of Hall element 165 andposition-detecting magnet 15 are designed such that the magnetic fluxproportional to the movement amount of AF movable part 11 crosses thedetection surface of Hall element 165. Accordingly, it is made possibleto obtain the Hall output proportional to the movement amount of AFmovable part 11.

As illustrated in FIGS. 9, 10, 11A, and 11B, control IC 161 is disposedto face first position-detecting magnet 15A such that the magnetic fluxof first position-detecting magnet 15A radially crosses the detectionsurface of Hall element 165. FIG. 11B is an enlarged view of theperiphery of first position-detecting magnet 15A. In the embodiments ofthe present invention, the detection surface of Hall element 165 isparallel to the XZ plane.

As described above, first and second position-detecting magnets 15A and15B are radially magnetized like permanent magnets 122A to 122D. In acase where position-detecting magnet 15 is disposed such that themagnetization direction is parallel to the optical-axis direction andthe layouts of the Hall element and the position-detecting magnet areset such that the zero-crossing (zero magnetic field) occurs at aneutral point (point where AF coil part 112 is not energized and AFmovable part 11 is magnetically stable), there is a risk that theneutral point of AF movable part 11 shifts from the designed positionsince the magnetic force acts on position-detecting magnet 15 in theoptical-axis direction due to the influence of magnetism by magnet part122.

In contrast, in the embodiments of the present invention,position-detecting magnet 15 is radially magnetized, so that themagnetic force in the optical-axis direction which acts onposition-detecting magnet 15 due to the influence of the magnetism bymagnet part 122 is decreased. Therefore, it is possible to prevent theneutral point of AF movable part 11 from shifting, so that the positiondetection accuracy in detecting the position of AF movable part 11 inthe optical-axis direction improves and the reliability improves.

Additionally, the magnetization direction of first position-detectingmagnet 15A is orthogonal to the detection surface of Hall element 165.Thus, the magnetic flux density of the magnetic flux which crosses thedetection surface is high, so that the Hall output can be obtained moreas compared with a case where the magnetization direction is parallel tothe detection surface of Hall element 165. Moreover, since themagnetization direction of first position-detecting magnet 15A is thesame as that of magnet part 122, the magnetic flux of firstposition-detecting magnet 15A which crosses the detection surface ofHall element 165 is not canceled by the magnetic flux of magnet part122. Accordingly, position-detecting magnet 15 can be downsized, so thatit is possible to achieve the miniaturization and weight reduction oflens driving device 1.

Furthermore, first position-detecting magnet 15A is disposed radiallynearer to Hall element 165 than to AF coil part 112. In other words,first position-detecting magnet 15A is disposed radially between Hallelement 165 and AF coil part 112. Accordingly, it becomes more difficultfor Hall element 165 to be influenced by AF coil part 112, so that theposition detection accuracy improves.

Note that, there is a risk that the linearity (straightness) of the Halloutput decreases in cases of the embodiments of the present invention,as compared with the case where the magnetization direction ofposition-detecting magnet 15 is made parallel to the optical-axisdirection and the position of the zero-crossing is set to the neutralpoint. Then, preferably, control IC 161 includes a linearity correctingfunction. This function makes it possible to secure the linearity of theHall output, so that the position detection accuracy in detecting theposition of AF movable part 11 in the optical-axis direction improves.

Additionally, first position-detecting magnet 15A is disposed to beoffset from Hall element 165 in the optical-axis direction. In theembodiments of the present invention, first position-detecting magnet15A is disposed to be offset from Hall element 165 on the lightreception side in the optical-axis direction. That is, center positionP_(M) of first position-detecting magnet 15A in the optical-axisdirection is offset from center position P_(H) of Hall element 165 onthe light reception side in the optical-axis direction (see FIG. 11B).

In this case, it is preferable that center position P_(M) of firstposition-detecting magnet 15A be disposed on the light reception siderelative to center position P_(H) of Hall element 165 in theoptical-axis direction after AF movable part 10 moves as far as possibletoward the image formation side in the optical-axis direction. That is,it is preferable that distance L_(MH) between the center of firstposition-detecting magnet 15A and the center of Hall element 165 in theoptical-axis direction be greater than a movement stroke of AF movablepart 11 on the image formation side in the optical-axis direction (thismovement stroke may hereinafter also be referred to as “downwardstroke”). In other words, it is preferable that the offset between firstposition-detecting magnet 15A and Hall element 165 in the optical-axisdirection be greater than a stroke of AF movable part 11 on the sideopposite to the offset side. In the embodiments of the presentinvention, distance L_(MH) between the center of firstposition-detecting magnet 15A and the center of Hall element 165 in theoptical-axis direction is twice the downward stroke or greater. Withthis configuration, the magnetic flux which crosses the detectionsurface of Hall element 165 increases or decreases monotonically alongwith automatic focusing operation, so that it is possible to calculatethe position of AF movable part 11 in the optical-axis direction easilyand accurately based on the Hall output.

Note that, first position-detecting magnet 15 may also be disposed to beoffset from Hall element 165 on the image formation side in theoptical-axis direction. In this case, it is preferable that distanceL_(MH) between the center of first position-detecting magnet 15A and thecenter of Hall element 165 in the optical-axis direction be greater thana movement stroke of AF movable part 11 on the light reception side inthe optical-axis direction (this movement stroke may hereinafter also bereferred to as “upward stroke”).

Thus, with the above-described configuration of Hall element 165 andposition-detecting magnet 15, it is made possible to achieve theminiaturization and weight reduction of lens driving device 1 and toimprove the reliability.

FIGS. 12A and 12B illustrate a configuration of AF control part 16. FIG.12A is a side view of AF control part 16 as seen from the base end sidein the Y direction. FIG. 12B illustrates a wiring pattern of AF printedwiring board 166.

As illustrated in FIGS. 12A and 12B, AF printed wiring board 166includes power-supply output terminals 162 a and 162 b, power-supplyinput terminals 162 c and 162 d, signal input terminals 162 e and 162 f,and a conductor pattern including interconnections 164 a to 164 f. InFIG. 12B, part of the conductor pattern formed on the front surface isindicated by the solid line, and part of the conductor pattern formed onthe back surface is indicated by the dotted line. Interconnections 164 ato 164 f are formed on the front and back surfaces of AF printed wiringboard 166. Those of interconnections 164 a to 164 f formed on the frontsurface and those of interconnections 164 a to 164 f formed on the backsurface of the base material are connected to each other via a throughhole (not illustrated). In AF printed wiring board 166, the front andback surfaces are covered with a resist film (whose reference numeral isomitted), and terminals 162 a to 162 f are exposed from the resist film.

Power-supply output terminals 162 a and 162 b are electrically connectedto AF supporting part 14 (lower plate springs 141 and 142). Power-supplyinput terminals 162 c and 162 d are electrically connected to AFpower-supply lines 171 and 172. Signal input terminals 162 e and 162 fare electrically connected to AF supporting part 13 (upper plate springs131 and 132). Each of terminals 162 a to 162 f is electrically connectedto control IC 161 via interconnections 164 a to 164 f. Bypass capacitor163 bypasses interconnection 164 c (power-supply line) andinterconnection 164 d (GND line) to reduce change in power-supplyvoltage.

Control IC 161 functions as a coil control part that controls theenergization current through AF coil part 112. Specifically, control IC161 controls the energization current through AF coil part 112 based onthe control signals provided via signal suspension wires 31A and 31B andAF supporting part 13 (AF signal lines) and based on the detectionresult (Hall output) by built-in Hall element 165 included in control IC161.

As illustrated in FIGS. 7 and 8, AF supporting part 13 elasticallysupports AF movable part 11 (lens holder 111) with respect to AF fixingpart 12 (magnet holder 121) at the light reception side of AF movablepart 10 in the optical-axis direction (AF supporting part 13 may alsohereinafter be referred to as “upper elastic supporting part 13”). Theconfiguration of upper elastic supporting part 13 and AF power-supplylines 171 and 172 is illustrated in FIG. 13. FIG. 13 is a plan view ofOIS movable part 10. Upper elastic supporting part 13 and AFpower-supply lines 171 and 172 are formed, for example, from titaniumcopper, nickel copper, stainless steel, and/or the like.

As illustrated in FIG. 13, upper elastic supporting part 13 and AFpower-supply lines 171 and 172, as a whole, are rectangular in planview, that is, have the same shape as magnet holder 121. Upper elasticsupporting part 13 is composed of two upper plate springs 131 and 132.Upper plate springs 131 and 132 and AF power-supply lines 171 and 172are disposed so as not to come into contact with one another on magnetholder 121. Upper plate springs 131 and 132 and AF power-supply lines171 and 172 are formed by performing an etching process on one sheetmetal, for example.

Upper plate springs 131 and 132 and AF power-supply lines 171 and 172are fixed to four corners of magnet holder 121. Bigger currents flowthrough AF power-supply lines 171 and 172 than currents flowing throughupper plate springs 131 and 132 which function as AF signal lines.Accordingly, AF power-supply lines 171 and 172 are disposed nearer to AFcontrol part 16 than upper plate springs 131 and 132 are to AF controlpart 16, and the path lengths between AF power-supply lines 171 and 172and AF control part 16 are made shorter. This configuration makes itpossible to eliminate the danger of power supply short.

Upper plate spring 131 includes lens-holder fixing portions 131 a and131 d to be fixed to lens holder 111, magnet-holder fixing portions 131b and 131 e to be fixed to magnet holder 121, and arm portions 131 c and131 f coupling lens-holder fixing portions 131 a and 131 d tomagnet-holder fixing portions 131 b and 131 e. Lens-holder fixingportions 131 a and 131 d are coupled to each other along lens housing111 a of lens holder 111. Arm portions 131 c and 131 f have a windingroad shape, and elastically deform when AF movable part 11 moves.

Upper plate spring 131 also includes wire connection portion 131 g andterminal connection portion 131 h. Wire connection portion 131 g extendscontinuously from magnet-holder fixing portion 131 e via two linkportions 131 i extending along the rim of magnet holder 121 frommagnet-holder fixing portion 131 e toward the corner portion. Terminalconnection portion 131 h extends from magnet-holder fixing portion 131 btoward AF printed wiring board 166.

Similarly, upper plate spring 132 includes lens-holder fixing portions132 a and 132 d, magnet-holder fixing portions 132 b and 132 e, and armportions 132 c and 132 f. Lens-holder fixing portions 132 a and 132 dare coupled to each other along lens housing 111 a of lens holder 111.Arm portions 132 c and 132 f have a winding road shape, and elasticallydeform when AF movable part 11 moves.

Upper plate spring 132 also includes wire connection portion 132 g andterminal connection portion 132 h. Wire connection portion 132 g extendscontinuously from magnet-holder fixing portion 132 e via two linkportions 132 i extending along the rim of magnet holder 121 frommagnet-holder fixing portion 132 e toward the corner portion. Terminalconnection portion 132 h extends from magnet-holder fixing portion 132 btoward AF printed wiring board 166.

Upper plate springs 131 and 132 are positioned with respect to lensholder 111 and fixed thereto by fitting positioning bosses (whosereference numerals are omitted) of upper-spring fixing portions 111 d oflens holder 111 in fixing holes (whose reference numerals are omitted)of lens-holder fixing portions 131 a, 131 d, 132 a, and 132 d. Upperplate springs 131 and 132 are also positioned with respect to magnetholder 121 and fixed thereto by fitting positioning bosses (whosereference numerals are omitted) of upper-spring fixing portions 121 g ofmagnet holder 121 in fixing holes (whose reference numerals are omitted)of magnet-holder fixing portions 131 b, 131 e, 132 b, and 132 e.

Wire connection portions 131 g and 132 g are soldered to andelectrically connected to signal suspension wires 31A and 31B (see FIGS.5 and 6). Terminal connection portions 131 h and 132 h are soldered toand electrically connected to signal input terminals 162 e and 162 f ofAF printed wiring board 166. Upper plate springs 131 and 132 function asAF signal lines adapted to provide AF control part 16 (control IC 161)with the control signal from signal suspension wires 31A and 31B.

AF power-supply line 171 includes magnet-holder fixing portion 171 a,wire connection portion 171 b, and terminal connection portion 171 c.Wire connection portion 171 b extends continuously from magnet-holderfixing portion 171 a via two link portions 171 d extending along the rimof magnet holder 121 from magnet-holder fixing portion 171 a toward thecorner portion. Terminal connection portion 171 c extends frommagnet-holder fixing portion 171 a toward AF printed wiring board 166.

Similarly, AF power-supply line 172 includes magnet-holder fixingportion 172 a, wire connection portion 172 b, and terminal connectionportion 172 c. Wire connection portion 172 b extends continuously frommagnet-holder fixing portion 172 a via two link portions 172 d extendingalong the rim of magnet holder 121 from magnet-holder fixing portion 172a toward the corner portion. Terminal connection portion 172 c extendsfrom magnet-holder fixing portion 172 a toward AF printed wiring board166.

AF power-supply lines 171 and 172 are positioned with respect to magnetholder 121 and fixed thereto by fitting positioning bosses (whosereference numerals are omitted) of upper-spring fixing portions 121 g ofmagnet holder 121 in fixing holes (whose reference numerals are omitted)of magnet-holder fixing portions 171 a and 172 a.

Wire connection portions 171 b and 172 b are soldered to andelectrically connected to power-supplying suspension wires 32A and 32B(see FIGS. 5 and 6). Terminal connection portions 171 c and 172 c aresoldered to and electrically connected to power-supply input terminals162 c and 162 d of AF printed wiring board 166. AF power-supply lines171 and 172 supply electricity from power-supplying suspension wires 32Band 32A to AF control part 16 (control IC 161).

Here, it is preferable that the solder used for electric connection doesnot contain flux. With such solder, it is made unnecessary to clean fluxafter soldering, so that it is possible to use the PAR or PAR alloy withpoor solvent resistance as the molding material of lens holder 111and/or magnet holder 121.

Although link portions 131 i, 132 i, 171 d, and 172 d extend frommagnet-holder fixing portions 131 e, 132 e, 171 a, and 172 a toward thecorner portions of upper plate springs 131 and 132 and AF power-supplylines 171 and 172, pairs of link portions 131 i, 132 i, 171 d, and 172 deach may include a portion extending inward from a confluent portion(corner portion) and wire connection portions 131 g, 132 g, 171 b, and172 b may be disposed at the tip ends of such inward extension portions.That is, link portions 131 i, 132 i, 171 d, and 172 d interposed betweenmagnet-holder fixing portions 131 e, 132 e, 171 a, and 172 a and wireconnection portions 131 g, 132 g, 171 b, and 172 b may bemulti-articulated while securing the linkage length. With thisconfiguration, stresses caused in link portions 131 i, 132 i, 171 d, and172 d during shake-correcting are mitigated, so that the tiltcharacteristics improve and also the resistance to impact such as dropimpact or the like improves.

In upper plate springs 131 and 132, damper materials 131 j, 131 k, 132j, and 132 k are provided between magnet-holder fixing portions 131 b,131 e, 132 b, and 132 e and arm portions 131 c, 131 f, 132 c, and 132 f.These damper materials 131 j, 131 k, 132 j, and 132 k reduce excessivemotions of arm portions 131 c, 131 f, 132 c, and 132 f during movementof lens holder 111 in the optical-axis direction, so that it is possibleto prevent interference between upper plate springs 131 and 132 andother members. Therefore, the stability of operation improves.

In upper plate springs 131 and 132, damper materials 131 m and 132 m areprovided between magnet-holder fixing portions 131 e and 132 e and wireconnection portions 131 g and 132 g. Also in AF power-supply lines 171and 172, damper materials 171 e and 172 e are provided betweenmagnet-holder fixing portions 171 a and 172 a and wire connectionportions 171 b and 172 b. Accordingly, generation of unwanted resonance(high-order resonant mode) is reduced, so that the stability ofoperation improves.

A cold-setting elastic adhesive based on silyl-group polymer can, forexample, be applied as damper materials 131 j, 131 k, 131 m, 132 j, 132k, 132 m, 171 e, and 172 e, and damper materials 131 j, 131 k, 131 m,132 j, 132 k, 132 m, 171 e, and 172 e can be easily applied, forexample, using a dispenser.

Note that, although upper plate springs 131 and 132 are used to functionas the AF signal lines and AF power-supply lines 171 and 172 areprovided separately from upper plate springs 131 and 132, upper platesprings 131 and 132 may be made to function as the AF power-supply linesand the AF signal lines may be provided separately from upper platesprings 131 and 132.

As illustrated in FIGS. 7 and 8, AF supporting part 14 elasticallysupports AF movable part 11 (lens holder 111) with respect to AF fixingpart 12 (magnet holder 121) at the image formation side of AF movablepart 10 in the optical-axis direction (AF supporting part 14 may alsohereinafter be referred to as “lower elastic supporting part 14”). Theconfiguration of lower elastic supporting part 14 is illustrated in FIG.14. FIG. 14 is a bottom view of OIS movable part 10. Like upper elasticsupporting part 13, lower elastic supporting part 14 is formed, forexample, from titanium copper, nickel copper, stainless steel, and/orthe like.

Lower elastic supporting part 14 is composed of four lower plate springs141 to 144. Lower plate springs 141 to 144 are formed by performing anetching process on one sheet metal, for example.

Lower plate springs 141 to 144 have substantially the same shape as oneanother. Lower plate springs 141 to 144 include lens-holder fixingportions 141 a to 144 a to be fixed to lens holder 111, magnet-holderfixing portions 141 b to 144 b to be fixed to magnet holder 121, and armportions 141 c to 144 c coupling lens-holder fixing portions 141 a to144 a to magnet-holder fixing portions 141 b and 144 b.

Arm portions 141 c to 144 c each include a winding path shape whichcurves along with the outer edge of each of permanent magnets 122A to122D, and each elastically deform when AF movable part 11 moves. Armportions 141 c to 144 c are formed in such a manner as to extend alongthe outer edges of permanent magnets 122A to 122D, and are arranged onthe light reception side relative to the undersurfaces of permanentmagnets 122A to 122D in the optical-axis direction at the neutral point.In other words, permanent magnets 122A to 122D protrude toward the imageformation side relative to lower plate springs 141 to 144 in theoptical-axis direction.

Additionally, lower plate springs 141 and 142 which are disposed on theside of AF control part 16 in the Y direction include coil connectionportions 141 d and 142 d and terminal connection portions 141 e and 142e. Coil connection portions 141 d and 142 d extend continuously fromlens-holder fixing portions 141 a and 142 a. Terminal connectionportions 141 e and 142 e extend from magnet-holder fixing portions 141 band 142 b toward AF printed wiring board 166.

Lower plate springs 141 to 144 are positioned with respect to lensholder 111 and fixed thereto by fitting positioning bosses oflower-spring fixing portions 111 g of lens holder 111 in fixing holes oflens-holder fixing portions 141 a to 144 a. Lower plate springs 141 to144 are also positioned with respect to magnet holder 121 and fixedthereto by fitting positioning bosses of lower-spring fixing portion 121g in fixing holes of magnet-holder fixing portions 141 b to 144 b.

Coil connection portions 141 d and 142 d are soldered to andelectrically connected to AF coil part 112 tied to tying parts 111 e oflens holder 111. Terminal connection portions 141 e and 142 e aresoldered to and electrically connected to power-supply output terminals162 a and 162 b of AF printed wiring board 166. As describe above, it ispreferable that the solder used for electric connection does not containflux. Lower plate springs 141 and 142 function as coil power-supplylines which supply electricity from control IC 161 to AF coil part 112.

FIGS. 15 and 16 are exploded perspective views of OIS fixing part 20.FIG. 15 is an upper perspective view and FIG. 16 is a lower perspectiveview.

As illustrated in FIGS. 15 and 16, OIS fixing part 20 includes base 21,coil board 22, XY-position detecting parts 23A and 23B, and the like.

XY-position detecting parts 23A and 23B are Hall elements that utilizethe Hall effect to detect change in magnetic field (hereinafter,XY-position detecting parts 23A and 23B may also be referred to as “Hallelements 23A and 23B”). Hall elements 23A and 23B are mounted on theback surface of coil board 22. Here, Hall elements 23A and 23B aredisposed at positions corresponding to OIS coils 221B and 221C. When OISmovable part 10 sways in the optical-axis-orthogonal plane, the magneticfield by magnet part 122 changes. Hall elements 23A and 23B detects thischange in magnetic field, and accordingly, the position of OIS movablepart 10 in the optical-axis-orthogonal plane is detected. The layouts ofHall elements 23A and 23B and magnet part 122 are designed such that themagnetic fluxes proportional to the movement amount of OIS movable part10 cross the detection surfaces of Hall elements 23A and 23B.Accordingly, it is made possible to obtain the Hall outputs proportionalto the movement amount of OIS movable part 10. Note that, another magnetfor XY-position detection may also be disposed to OIS movable part 10 inaddition to magnet part 122.

Base 21 is a supporting member adapted to support coil board 22. FIG.17A is a plan view of base 21 and FIG. 17B is a bottom view of base 21.In FIGS. 17A and 17B, the inside of base 21 is shown transparently.

Base 21 is a rectangular member in plan view, and includes circularopening 21 a at the center of base 21. Base 21 includes, at its rimportion, terminal attachment portions 21 b at positions corresponding toterminal portions 220B of coil board 22.

Base 21 includes, at the rim portion of opening 21 a, Hall-elementhousings 21 c adapted to house Hall elements 23A and 23B. Base 21 alsoincludes terminal housings 21 d adapted to house power-supplyingterminals 223 and 224 and signal terminals 225 and 226 of coil board 22.Terminal housings 21 d are formed to protrude radially outward beyondterminal attachment portion 21 b.

Base 21 includes notches 21 f at the four corners of the rim portion ofbase 21. Base 21 includes, on its upper surface, first reinforcing ribs21 g at the rims of notches 21 f and also includes second reinforcingribs 21 h at the rim of base 21 along the Y direction. Base 21 alsoincludes, on its undersurface, third reinforcing ribs 21 j at the rimsof notches 21 f. Second reinforcing ribs 21 h each include protrusion 21i used for determining the placing direction of coil board 22.Reinforcing ribs 21 g, 21 h, and 21 j increase the mechanical strengthof base 21, thus making it possible to achieve the thickness reductionof base 21. In particular, since base 21 includes second reinforcingribs 21 h extending along the rim portion, base 12 can have a structurerobust against distortion.

Base 21 also includes, on its undersurface, adhesive-fixing portions 21k at portions of the rim of base 21 extending along the Y direction.When cover 2 is attached to base 21, an adhesive (for example, epoxyresin) is applied to adhesive-fixing portions 21 k.

Base 21 includes four embedded terminal metal fixtures 211 to 214.Terminal metal fixtures 211 to 214 are formed integrally with base 21,for example, by insert molding. Terminal metal fixtures 211 to 214 areeach L-shaped and disposed along the four corners of base 21. One ends211 a to 214 a of terminal metal fixtures 211 to 214 are exposed fromterminal housings 21 d of base 21.

Intermediate portions (bent portions) 211 b to 214 b of terminal metalfixtures 211 to 214 are exposed from notches 21 f of the four corners ofbase 21. Intermediate portions 211 b to 214 b are arranged on the imageformation side in the optical-axis direction relative to the surface ofbase 21 located on the light reception side in the optical-axisdirection. One ends of suspension wires 30 are connected to intermediateportions 211 b to 214 b of terminal metal fixtures 211 to 214. Thus, itis made possible to secure the effective length of suspension wire 30while achieving the height reduction of lens driving device 1.Accordingly, fracture due to the metal fatigue or the like of suspensionwire 30 can be reduced, so that the reliability of lens driving device 1improves.

Other ends 211 c to 214 c of terminal metal fixtures 211 to 214 areexposed from adhesive-fixing portions 21 k of base 21 and, when cover 2is attached to base 21, the adhesive is applied to other ends 211 c to214 c. The anchor effect increases the adhesive strength for attachmentof cover 2 to base 21, thus improving the resistance to drop impact.

Terminal metal fixture 211 is soldered to and electrically connected topower-supplying terminal 223 of coil board 22 and to power-supplyingsuspension wire 32A. Terminal metal fixture 212 is soldered to andelectrically connected to power-supplying terminal 224 of coil board 22and to power-supplying suspension wire 32B. Terminal metal fixture 213is soldered to and electrically connected to signal terminal 225 of coilboard 22 and to signal suspension wire 31B. Terminal metal fixture 214is soldered to and electrically connected to signal terminal 226 of coilboard 22 and to signal suspension wire 31A.

Base 21 includes protruding portions 21 e protruding on the lightreception side in the optical-axis direction such that adjacent terminalmetal fixtures 211 and 212 are isolated from each other and adjacentterminal metal fixtures 213 and 214 are isolated from each other.Protruding portions 21 e are disposed between ends 211 a and 212 a ofterminal metal fixtures 211 and 212 and between ends 213 a and 214 a ofterminal metal fixtures 213 and 214, respectively. Protruding portions21 e spatially separate terminal metal fixtures 211A and 211B from eachother and terminal metal fixtures 211C and 211D from each other tosecure the insulation property, so as to improve the safety andreliability.

In the embodiments of the present invention, like lens holder 111 andmagnet holder 121, base 21 is formed from a molding material consistingof polyarylate (PAR) or a PAR alloy (e.g. PAR/PC) which is a mixture ofmultiple resin materials including PAR. With this molding material, theweld strength is increased and, thus, the toughness and impactresistance can be secured even when base 21 is thin-walled. It is thuspossible to make the external size of lens driving device 1 smaller andto achieve the miniaturization and height reduction.

Additionally, base 21 is preferably formed by injection molding usingmultiple gates. In this case, the gate diameter is preferably 0.3 mm orgreater. Such injection molding brings about a better fluidity duringmolding, so as to allow thin-wall molding and besides, to make itpossible to prevent occurrence of sink marks even when the PAR or PARalloy is used as molding material.

It is preferable that the molding material consisting of the PAR or PARalloy be conductive and, in particular, have a volume resistivity offrom 10⁹ Ω·cm to 10¹¹ Ω·cm. For example, it is possible to easily impartconductivity to an existing PAR or PAR alloy by mixing carbon nanotubesinto such an existing PAR or PAR alloy. At this time, suitableconductivity can be imparted by adjusting the content of carbonnanotubes. Such adjustment makes it possible to reduce electrificationof base 21 and thus to prevent occurrence of static electricity.

Note that, it is preferable that the PAR or PAR alloy as the moldingmaterial of base 21 contain fluoride when the movement of AF movablepart 11 (lens holder 111) in the optical-axis direction is restricted bylens holder 111 and base 21. By the contained fluoride, theintermolecular forces become weaker, so that the adsorptive power ofportions of base 21 coming into contact with lens holder 111 decreasesand the slidability improves. Accordingly, it is possible to preventdust generation due to friction during contact between lens holder 111and base 21.

As illustrated in FIGS. 15 and 16, coil board 22 is a rectangular boardin plan view like base 21 and includes circular opening 22 a at thecenter of coil board 22. Coil board 22 is a multilayer printed wiringboard in which multiple unit layers consisting of conductor layer L1 andinsulating layer L2 (see FIG. 18) are stacked on one another. In theembodiments of the present invention, OIS coil part 221, externalterminals 222, and a conductor pattern (not illustrated) includingpower-supply lines used for connecting external terminals 222 to OIScoil part 221 are integrally formed in coil board 22. FIG. 18illustrates layer structures at points P1 to P6 of coil board 22 in FIG.15.

In coil board 22, conductor layer L1 is formed from a copper foil, forexample. Insulating layers L2 is formed from a liquid crystal polymer(LCP), for example. Note that, resist layers L3 and L4 are formed on thefront and back surfaces of coil board 22 when necessary.

Coil board 22 includes main board portion 220A, terminal portions 220B,and coupling portions 220C. The number of stacked layers of the firststack structure forming main board portion 220A is greater than that ofthe second stack structure forming terminal portions 220B, and thenumber of stacked layers of second stack structure is greater than thatof the third stack structure forming coupling portions 220C. In theembodiments of the present invention, main board portion 220A is formedfrom nine unit layers, terminal portions 220B are each formed from threeunit layers, and coupling portions 220C are each formed from one unitlayer.

Main board portion 220A includes OIS coil part 221 at a position whereOIS coil part 221 faces magnet part 122 in the optical-axis direction.OIS coil part 221 is composed of four OIS coils 221A to 221Dcorresponding to permanent magnets 122A to 122D. OIS coils 221A to 221Dare formed inside main board portion 220A in the manufacturing processof coil board 22. In the embodiments of the present invention, OIS coils221A to 221D are formed from seven unit layers (layer Nos. 3 to 9) ofthe nine unit layers of main board portion 220A. The remaining two unitlayers (layer Nos. 1 and 2) of main board portion 220A are connectionlayers in which the conductor pattern including an interconnectionconnecting OIS coil part 221 and Hall elements 23A and 23B to externalterminals 222 is formed.

The sizes and arrangement of OIS coils 221A to 221D and permanentmagnets 122A to 122D are set such that the radial edges of permanentmagnets 122A to 122D are respectively within the coil sectional widthsof OIS coils 221A to 221D, that is, such that the magnetic fieldsemitted from the bottoms of permanent magnets 122A to 122D cross twoopposite sides of OIS coils 221 to 221D and then return to permanentmagnets 122A to 122D. Here, OIS coils 221A to 221D each have the sameshape as those of permanent magnets 122A to 122D as seen in plan view(in this case, substantially isosceles trapezoid). Thus, it is madepossible to generate efficiently the driving force (electromagneticforce) for causing OIS movable part 10 to sway in theoptical-axis-orthogonal plane.

OIS coils 221A and 221C are connected and the OIS coils 221B and 221Dare connected to each other, and two pairs of OIS coils 221A and 221Cand of OIS coils 221B and 221D are energized respectively with the samecurrents. Permanent magnets 122A and 122C and OIS coils 221A and 221Cconstitute the OIS voice coil motor causing OIS movable part 10 to swayin the U direction. Permanent magnets 122B and 122D and OIS coils 221Band 221D constitute the OIS voice coil motor causing OIS movable part 10to sway in the V direction.

The corners of main board portion 220A are formed in the shapecorresponding to first reinforcing ribs 21 g of base 21 (cut portions 22c). Additionally, rim portions 22 d extending in the Y direction alongmain board portion 220A restricts the movement of AF movable part 11toward the image formation side in the optical-axis direction by cominginto contact with holder-side contact portions 111 i when AF movablepart 11 moves toward the image formation side in the optical-axisdirection (hereinafter, these rim portions 22 d are referred to as“base-side contact portions 22 d”). The side surface of each ofbase-side contact portions 22 d is formed in the shape corresponding toeach of second reinforcing ribs 21 h of base 21.

Regions of the upper surface (surface on the light reception side in theoptical-axis direction) of main board portion 220A where OIS coil part221 is disposed are covered by resist layer L3. In contrast, resistlayer L3 is not formed on other regions of the upper surfacecorresponding to base-side contact portions 22 d (portions coming intocontact with AF movable part 11) and conductor layer L1 is exposed onsuch regions. Note that, insulating layer L2 may also be exposed on theregions of the upper surface corresponding to base-side contact portions22 d. Such a configuration makes it possible to stabilize the attitudeof AF movable part 11 when the movement of AF movable part 11 toward theimage formation side in the optical-axis direction is restricted.Additionally, it is possible to prevent dust generation due to frictionduring contact between holder-side contact portion 111 i and the uppersurface regions of base-side contact portions 22 d.

Hall elements 23A and 23B are mounted on the undersurface of main boardportion 220A. Main board portion 220A also includes power-supplyingterminals 223 and 224 and signal terminals 225 and 226. Power-supplyingterminals 223 and 224 and signal terminals 225 and 226 are electricallyconnected to terminal metal fixtures 211 to 214 (ends 211 a to 214 aexposed from terminal housings 21 d) of base 21 by soldering. OIS coils221A to 221D, Hall elements 23A and 23B, power-supplying terminals 223and 224, and signal terminals 225 and 226 are electrically connected tothe external terminals 222 of terminal portions 220B via the conductorpattern (not illustrated) formed in coil board 22.

The conductor pattern of coil board 22 includes power-supply lines (twolines (not illustrated)) for supplying electric power to OIS movablepart 10 (AF control part 16), power-supply lines (two lines×2 (notillustrated)) for supplying electric power to OIS coils 221A to 221D,power-supply lines (two lines×2 (not illustrated)) for supplyingelectric power to Hall elements 23A and 23B, signal lines (two lines(not illustrated)) for detection signals output from Hall elements 23Aand 23B, and signal lines (two lines (not illustrated)) for controlsignals used for controlling the automatic focusing operation in OISmovable part 10.

Terminal portions 220B are provided to face each other in the Ydirection. Terminal portions 220B each include eight external terminals222 and the total number of external terminals amounts to 16. Externalterminals 222 include power-supplying terminals (two terminals) for AFcontrol part 16, signal terminals (two terminals) for AF control part16, power-supplying terminals (four terminals) for OIS coil part 221,power-supplying terminals (four terminals) and signal terminals (fourterminals) for Hall elements 23A and 23B.

Coupling portions 220C couple main board portion 220A and terminalportions 220B to each other. Coupling portions 220C are each roundedsuch that each of terminal portions 220B is hung from main board portion220A. Terminal portions 220B extend substantially perpendicular to mainboard portion 220A, accordingly. Each of coupling portions 220C alsoincludes opening 22 b in the approximate middle in the X direction.

In the embodiments of the present invention, the number of stackedlayers of coupling portions 220C is smaller than those of main boardportion 220A and terminal portions 220B. Thus, it is made possible torelatively easily bend and round coupling portions 220C.

OIS fixing part 20 is assembled by adhering main board portion 220A andterminal portions 220B of coil board 22 to base 21. At this time, cutportions 22 c of coil board 22 are engaged with first reinforcing ribs21 g of base 21. Additionally, base-side contact portions 22 d of coilboard 22 are engaged with second reinforcing ribs 21 h and protrusions21 i formed to second reinforcing ribs 21 h of base 21. Additionally,the side portions of terminal housings 21 d of base 21 are engaged withopenings 22 b in coil board 22. With this configuration, coil board 22is accurately positioned and firmly fixed with respect to base 21.

In the embodiments of the present invention, base 21 and coil board 22are adhered to each other with an elastic epoxy resin material. Base 21and coil board 22 are adhesively integrated, so that the mechanicalstrength of OIS fixing part 20 is increased. It is thus made possible toachieve thin-walled base 21 and/or coil board 22 while securing adesired resistance to drop impact.

It is preferable that the back surface of main board portion 220A(surface on the image formation side in the optical-axis direction) becovered with resist layer L4 and conductor layer L1 be exposed fromparts of resist layer L4 as illustrated in FIG. 19A. This configurationincreases the adhesive strength between base 21 and coil board 22 so asto make it possible to make the structure of OIS fixing part 20 robust.

Alternatively, as illustrated in FIG. 19B, the back surface of mainboard portion 220A may also be covered with magnetic plating layer 227.Magnetic plating layer 227 is a plate member obtained by plating a NiCuplate having a thickness of 30 μm to 50 μm with Ni (5 μm to 10 μm), forexample. With this magnetic plating layer 227, OIS fixing part 20 canhave a robust structure and the magnetic flux crossing OIS coil part 221increases, so that the thrust for shake-correcting operation can beincreased.

In lens driving device 1, one ends of signal suspension wires 31A and31B are electrically connected to wire connection portions 131 g and 132g of upper plate springs 131 and 132, respectively. The other ends ofsignal suspension wires 31A and 31B are electrically connected toterminal metal fixtures 214 and 213 (portions 214 b and 213 b exposedfrom notches 21 f) of base 21. Terminal metal fixtures 214 and 213 ofbase 21 are also electrically connected to signal terminals 226 and 225of coil board 22.

Additionally, one ends of power-supplying suspension wires 32A and 32Bare electrically connected to wire connection portions 171 b and 172 bof AF power-supply lines 171 and 172, respectively. The other ends ofpower-supplying suspension wires 32A and 32B are electrically connectedto terminal metal fixtures 211 and 212 (portions 211 b and 212 b exposedfrom notches 21 f) of base 21. Terminal metal fixtures 211 and 212 ofbase 21 are also electrically connected to power-supplying terminals 223and 224 of coil board 22.

Damper materials 33 and 34 are disposed to portions in which signalsuspension wires 31A and 31B are connected to upper plate springs 131and 132 and terminal metal fixtures 214 and 213, and are also disposedto portions in which power-supplying suspension wires 32A and 32B areconnected to AF power-supply lines 171 and 172 and terminal metalfixtures 211 and 212. That is, damper materials 33 and 34 are disposedto the fixed ends of signal suspension wires 31A and 31B and ofpower-supplying suspension wires 32A and 32B (see FIG. 20).Specifically, damper materials 33 are disposed in such a manner as tosurround signal suspension wires 31A and 31B and power-supplyingsuspension wires 32A and 32B on the undersurfaces (surfaces on the imageformation side in the optical-axis direction) of upper plate springs 131and 132 and of AF power-supply lines 171 and 172. Additionally, dampermaterials 34 are disposed in such a manner as to surround signalsuspension wires 31A and 31B and power-supplying suspension wires 32Aand 32B on the upper surfaces (surfaces on the light reception side inthe optical-axis direction) of terminal metal fixtures 214, 213, 211,and 212. Damper materials 33 and 34 are disposed. These damper materials33 and 34 distribute the stress which would arise in each of signalsuspension wires 31A and 31B. Accordingly, fracture due to the metalfatigue or the like of suspension wire 30 can be reduced, so that thereliability of lens driving device 1 improves.

In lens driving device 1, a control signal is supplied to AF controlpart 16 from coil board 22 via base 21, signal suspension wires 31A and31B, and upper plate springs 131 and 132. Additionally, electricity issupplied to AF control part 16 from coil board 22 via base 21,power-supplying suspension wires 31A and 32B, and AF power-supply lines171 and 172. Moreover, electricity is supplied to AF coil part 112 fromAF control part 16 via lower plate springs 141 and 142. In this way, theoperational control of AF movable part 11 (specifically, control of theenergization current flowing through AF coil part 112) is implemented.

Since control IC 161 of AF control part 16 includes Hall element 165 andthe coil control part, and the closed-loop control based on thedetection result of Hall element 165 is completed in AF control part 16,it is enough only to supply electricity and the control signal to AFcontrol part 16 by four suspension wires 31A, 31B, 32A, and 32B.Accordingly, the configurations of suspension wires 30 used for drivingAF coil part 112 and Hall element 165 can be simplified and thereliability of the AF driving part can be improved.

Additionally, the terminals to be disposed on AF printed wiring board166 in which control IC 161 is mounted are arranged distributedly, sothat the number of degrees of design freedom increases in comparisonwith the case where the wiring lines (AF power-supply lines, AF signallines, and coil power-supply lines) are routed together on the lightreception side or on the image formation side of lens driving device 1in the optical-axis direction. Additionally, the soldering area can beenlarged and, it is thus made possible to prevent a faulty connectionand to improve reliability.

When the shake correction is performed in lens driving device 1, OIScoils 221A to 221D are energized. Specifically, the energizationcurrents through OIS coils 221A to 221D are controlled by the OISdriving part based on the detection signal from a shake detection part(not illustrated) (for example, a gyro sensor) such that the shake ofcamera module A can be canceled. At this time, by feedback of thedetection result of Hall elements 23A and 23B, it is made possible toaccurately control the sway of OIS movable part 10.

When OIS coils 221A to 221D are energized, the Lorentz forces arise atOIS coils 221A to 221D by interaction between the magnetic fields ofpermanent magnets 122A to 122D and the currents flowing through OIScoils 221A to 221D (Fleming's left hand rule). The directions of theLorentz forces are directions (the V or U direction) orthogonal both tothe direction of the magnetic fields (Z direction) at the long sideportions of OIS coils 221A to 221D and to the directions of currents(the U or V direction). Since OIS coils 221A to 221D are fixed, reactiveforces act on permanent magnets 122A to 122D. With these reactive forcesserving as the driving forces of the OIS voice coil motor, OIS movablepart 10 including magnet part 122 sways in the XY plane, so that theshake correction is performed.

When automatic focusing is performed in lens driving device 1, AF coilpart 112 is energized. The energization current through AF coil part 112is controlled by AF control part 16 (control IC 161). Specifically,control IC 161 controls the energization current to AF coil part 112based on the control signals provided via signal suspension wires 31Aand 31B and upper plate springs 131 and 132 and based on the detectionresult by built-in Hall element 165 included in control IC 161.

Note that, in an non-energization state where automatic focusing is notbeing performed, AF movable part 11 is brought into a state (neutralpoint) where AF movable part 11 is suspended between an infinityposition and a macro position by upper plate springs 131 and 132 andlower plate springs 141 to 144. That is, in OIS movable part 10, AFmovable part 11 (lens holder 111) is elastically supported to bedisplaceable on both sides in the Z direction while being positionedwith respect to AF fixing part 12 (magnet holder 121) by upper platesprings 131 and 132 and lower plate springs 141 to 144.

When AF coil part 112 is energized, the Lorentz force arises at AF coilpart 112 by interaction between the magnetic field of magnet part 122and the current flowing through AF coil 112 part. The direction of theLorentz force is the direction (the Z direction) orthogonal to thedirection of the magnetic field (U or V direction) and to the directionof current flowing through AF coil part 112 (V or U direction). Sincemagnet part 122 is fixed, a reactive force acts on AF coil part 112.With this reactive force serving as the driving force of the AF voicecoil motor, AF movable part 11 including AF coil part 112 moves in theoptical-axis direction, so that focusing is performed.

In AF control part 16 of lens driving device 1, the closed loop controlis performed based on the detection signal obtained by built-in Hallelement 165 included in control IC 161. With the closed-loop controlsystem, it is unnecessary to take into consideration the hysteresischaracteristics of the voice coil motor, and it is made possible todirectly detect that the position of AF movable part 11 is stabilized.Moreover, the present invention is also applicable to automatic focusingof an image surface detection system. Thus, since the responseperformance is high, higher-speed automatic focusing operation can beachieved.

As described above, lens driving device 1 includes the AF driving partincluding AF coil part 112 to be disposed at the periphery of the lenspart (not illustrated), magnet part 122 (AF magnet part) to be disposedto be radially spaced apart from AF coil part 112, and AF supportingparts 13 and 14 configured to support, with respect to AF fixing part 12including magnet part 122, AF movable part 11 including AF coil part 11such that AF movable part 11 is movable in the optical-axis direction.The AF driving part is configured to perform automatic focusing byutilizing the driving force of the voice coil motor composed of AF coilpart 112 and magnet part 122. Lens driving device 1 also includes theOIS driving part including magnet part 122 (shake-correcting magnetpart) to be disposed in the AF driving part, OIS coil part 221 to bedisposed to be spaced apart from magnet part 122 in the optical-axisdirection, and OIS supporting part 30 configured to support, withrespect to OIS fixing part 20 including OIS coil part 221, OIS movablepart 10 including magnet part 122 such that OIS movable part 10 is ableto sway in the optical-axis-orthogonal plane. OIS supporting part 30 isconfigured to perform shake correction by utilizing the driving force ofthe voice coil motor composed of OIS coil part 221 and magnet part 122.

In lens driving device 1, AF supporting parts 13 and 14 include upperelastic supporting part 13 configured to couple AF movable part 11 andAF fixing part 12 together at the light reception side in theoptical-axis direction, and lower elastic supporting part 14 configuredto couple AF movable part 11 and AF fixing part 12 together at the imageformation side in the optical-axis direction. OIS supporting part 30includes: a pair of power-supplying suspension wires 32A and 32Bincluding one ends to be connected to AF fixing part 12 and the otherends to be connected to OIS fixing part 20; and a pair of signalsuspension wires 31A and 31B including one ends to be connected to AFfixing part 12 and the other ends to be connected to OIS fixing part 20.AF movable part 11 includes: lens holder 111 including cylindrical lenshousing 111 a configured to hold the lens part and the coil windingportion on which AF coil part 112 is wound; and first position-detectingmagnet 15A (position-detecting magnet) to be disposed to lens holder111. The AF fixing part is electrically connected to power-supplyingsuspension wires 32A and 32B and to signal suspension wires 31A and 31B,and includes AF control part 16 configured to control the energizationcurrent through AF coil part 112. The AF driving part includes a pair ofAF power-supply lines 171 and 172 to be connected to the pair ofpower-supplying suspension wires 32A and 32B, a pair of signal lines tobe connected to the pair of signal suspension wires 31A and 31B, and acoil power-supply line configured to electrically connect the AF controlpart to AF coil part 112. AF control part 16 includes: control IC 161including built-in Hall element 165 and the built-in coil control partconfigured to control the energization current through AF coil part 112based on the control signal provided via signal suspension wires 31A and31B and based on the detection result of Hall element 165; and AFprinted wiring board 166 on which control IC 161 is mounted. Upperelastic supporting part 13 (upper plate springs 131 and 132) functionsas the signal lines, and the lower elastic supporting part (lower platesprings 141 and 142) functions as the coil power-supply lines. Notethat, upper elastic supporting part 13 may also function as the AFpower-supply lines, and an AF signal line may also be providedseparately from upper elastic supporting part 13.

Additionally, in lens driving device 1, AF fixing part 12 includes Hallelement 165 that detects the position of AF movable part 11 in theoptical-axis direction. AF movable part 11 includes firstposition-detecting magnet 15A (position-detecting magnet) arranged nearHall element 165. Both of magnet part 122 and first position-detectingmagnet 15A are radially magnetized.

Additionally, in lens driving device 1, OIS fixing part 20 includes coilboard 22 consisting of the multilayer printed wiring board in whichmultiple unit layers consisting of conductor layer L1 and insulatinglayer L2 are stacked on one another, and base 21 on which coil board 22is placed. OIS coil part 221, external terminals 222, and the conductorpattern (not illustrated) including the power-supply lines used forconnecting external terminals 222 to OIS coil part 221 are integrallyformed in coil board 22.

Additionally, in lens driving device 1, AF movable part 11 includes lensholder 111 adapted to hold the lens part and AF coil part 112, AF fixingpart 12 includes magnet holder 121 adapted to hold magnet part 122 (AFmagnet part), and OIS fixing part 20 includes base 21 to which OIS coilpart 221 is disposed. Lens holder 111, magnet holder 121, and base 21are formed from a molding material consisting of polyarylate (PAR) or aPAR alloy which is a mixture of multiple resin materials includingpolyarylate. Note that, at least one of lens holder 111, magnet holder121, and bases 21 may be formed from the molding material consisting ofthe PAR or PAR alloy.

According to lens driving device 1, it is possible to achieve theminiaturization and weight reduction and also to improve thereliability.

While the invention made by the present inventor has been specificallydescribed based on the preferred embodiments, it is not intended tolimit the present invention to the above-mentioned preferred embodimentsbut the present invention may be further modified within the scope andspirit of the invention defined by the appended claims.

For example, although the embodiments of the present invention have beendescribed in relation to the case where one control IC 161 includesbuilt-in Hall element 165 and the built-in coil control part (notillustrated), Hall element 165 and the coil control part may be mounted,as separate ICs, on AF printed wiring board 166.

Additionally, by way of another example, the AF signal lines and AFpower-supply lines disposed in the AF driving part may be providedseparately from upper elastic supporting part 13. However, since thismodification results in a complicated structure, it is preferable thatupper elastic supporting part 13 function as the AF signal lines or theAF power-supply line.

While smartphone M serving as a camera-equipped mobile terminal has beendescribed in the embodiments as an example of the camera-mounted deviceincluding camera module A, the present invention is applicable to acamera-mounted device serving as an information device or a transportingdevice. The camera-mounted device serving as an information device is aninformation device including a camera module and a control section thatprocesses image information obtained with the camera module, andexamples of such a camera-mounted device include a camera-equippedmobile phone, a note-type personal computer, a tablet terminal, a mobilegame machine, a web camera, and a camera-equipped in-vehicle apparatus(for example, a rear-view monitor apparatus or a drive recorderapparatus). In addition, the camera-mounted device serving as atransporting device is a transporting device including a camera moduleand a control part that processes an image obtained with the cameramodule, and examples of such a camera-mounted device include anautomobile.

FIGS. 21A and 21B illustrate automobile V serving as the camera-mounteddevice in which in-vehicle camera module VC (Vehicle Camera) is mounted.FIG. 21A is a front view of automobile V and FIG. 21B is a rearperspective view of automobile V. In automobile V, camera module Adescribed in the embodiments is mounted as in-vehicle camera module VC.As illustrated in FIGS. 21A and 21B, in-vehicle camera module VC may,for example, be attached to the windshield so as to face forward, or tothe rear gate so as to face backward. Onboard camera module VC is usedfor rear monitoring, drive recording, collision avoidance control,automatic drive control, and the like.

The embodiments disclosed herein are merely an exemplification in everyrespect and should not be considered as limitative. The scope of thepresent invention is specified by the claims, not by the above-mentioneddescription. The scope of the present invention is intended to includeall modifications in so far as they are within the scope of the appendedclaims or the equivalents thereof.

REFERENCE SIGNS LIST

-   1 Lens Driving Device-   2 Cover-   10 OIS Movable Part (AF Driving Part)-   11 AF Movable Part-   12 AF Fixing Part-   13 Upper Elastic Supporting Part (AF Supporting Part)-   14 Lower Elastic Supporting Part-   15 Position-Detecting Magnet-   16 AF Control Part-   20 OIS Fixing Part-   21 Base-   22 Coil Board-   30 OIS Supporting Part-   31A, 31B Signal Suspension Wire-   32A, 32B Power-Supplying Suspension Wire-   111 Lens Holder-   112 AF Coil Part-   121 Magnet Holder-   122 Magnet Part (AF Magnet Part, OIS Magnet Part)-   122A to 122D Permanent Magnets-   131, 132 Upper Plate Spring (AF Signal Line)-   141, 142 Lower Plate Spring (Coil Power-Supply Line)-   161 Control IC-   162 a, 162 b Power-Supply Output Terminal-   162 c, 162 d Power-Supply Input Terminal-   162 e, 162 f Signal Input Terminal-   163 Bypass Capacitor-   164 a to 164 f Interconnection-   165 Hall Element-   166 AF Printed Wiring Board-   171, 172 AF Power-Supply Line-   221 OIS Coil Part-   M Smartphone-   A Camera Module

1. A lens driving device, comprising: an auto-focusing driving partincluding: an auto-focusing coil part to be disposed at a periphery of alens part; an auto-focusing magnet part to be disposed to be radiallyspaced apart from the auto-focusing coil part; and an auto-focusingsupporting part configured to support an autofocus movable part to bemovable in an optical-axis direction with respect to an autofocus fixingpart, the autofocus movable part including the auto-focusing coil part,the autofocus fixing part including the auto-focusing magnet part, andthe auto-focusing driving part being configured to perform automaticfocusing by utilizing a driving force of a voice coil motor composed ofthe auto-focusing coil part and the auto-focusing magnet part, and ashake-correcting driving part including: a shake-correcting magnet partto be disposed in the auto-focusing driving part; a shake-correctingcoil part to be disposed to be spaced apart from the shake-correctingmagnet part in the optical-axis direction; and a shake-correctingsupporting part configured to support a shake-correcting movable part tobe able to sway in an optical-axis-orthogonal plane with respect to ashake-correcting fixing part, the shake-correcting movable partincluding the shake-correcting magnet part, the shake-correcting fixingpart including the shake-correcting coil part, and the shake-correctingdriving part being configured to perform shake correction by utilizing adriving force of an another voice coil motor composed of theshake-correcting coil part and the shake-correcting magnet part, whereinthe auto-focusing supporting part includes: an upper elastic supportingpart configured to couple the autofocus movable part and the autofocusfixing part together at a light reception side in the optical-axisdirection, and a lower elastic supporting part configured to couple theautofocus movable part and the autofocus fixing part together at animage formation side in the optical-axis direction, wherein theshake-correcting supporting part includes: a pair of power-supplyingsuspension wires each of which includes one end to be connected to theautofocus fixing part and the other end to be connected to theshake-correcting fixing part, and a pair of signal suspension wires eachof which includes one end to be connected to the autofocus fixing partand the other end to be connected to the shake-correcting fixing part,wherein the autofocus movable part includes: a lens holder including acylindrical lens housing and a coil winding portion, the cylindricallens housing being configured to hold the lens part, the coil windingportion being a portion on which the auto-focusing coil part is wound,and a position-detecting magnet to be disposed to the lens holder,wherein the autofocus fixing part includes an auto-focusing control partto be electrically connected to the pair of power-supplying suspensionwires and the pair of signal suspension wires, the auto-focusing controlpart being configured to control an energization current through theauto-focusing coil part, wherein the auto-focusing driving partincludes: a pair of auto-focusing power-supply lines to be connected tothe pair of power-supplying suspension wires, a pair of signal lines tobe connected to the pair of signal suspension wires, and a coilpower-supply line configured to electrically connect the auto-focusingcontrol part to the auto-focusing coil part, wherein the auto-focusingcontrol part includes: a control IC including a built-in Hall elementand a built-in coil control part, the built-in coil control part beingconfigured to control the energization current through the auto-focusingcoil part based on a control signal to be provided via the pair ofsignal suspension wires and based on a detection result of the built-inHall element, and an auto-focusing printed wiring board on which thecontrol IC is mounted, wherein the upper elastic supporting partfunctions at least as the pair of auto-focusing power-supply lines orthe pair of signal lines, and wherein the lower elastic supporting partfunctions as the coil power-supply line.
 2. The lens driving deviceaccording to claim 1, wherein the auto-focusing control part is disposednearer to a first connected portion than to a second connected portion,the first connected portion being a portion in which the pair ofauto-focusing power-supply lines is connected to the pair ofpower-supplying suspension wires, the second connected portion being aportion in which the pair of signal lines is connected to the pair ofsignal suspension wires.
 3. The lens driving device according to claim1, wherein: the upper elastic supporting part functions as the pair ofsignal lines, and the pair of auto-focusing power-supply lines isprovided separately from the upper elastic supporting part.
 4. The lensdriving device according to claim 1, wherein the pair of auto-focusingpower-supply lines and the pair of signal lines are formed by etchingone sheet metal.
 5. The lens driving device according to claim 1,wherein: the lens holder includes two tying parts to which both ends ofthe auto-focusing coil part are respectively tied, and the two tyingparts are disposed near the auto-focusing control part.
 6. The lensdriving device according to claim 5, wherein the lens holder includes aprotruding portion to be disposed between the two tying parts.
 7. Acamera module, comprising: the lens driving device according to claim 1;a lens part to be mounted on the autofocus movable part; and an imagecapturing part configured to capture a subject image imaged by the lenspart.
 8. A camera-mounted device that is an information device or atransporting device, the camera-mounted device comprising: the cameramodule according to claim 7; and a control part configured to processimage information obtained by the camera module.